Headphone apparatus for reducing circumference noise

Abstract

A headphone apparatus includes a speaker unit accommodated in an accommodating member of an open-air type, a microphone disposed at a front side of the speaker unit, a circuit arrangement mounted on a circuit board in the speaker unit including a filter for lowering a level of a high frequency component of a signal picked up by the microphone, and a negative feedback loop for feeding back an output of the filter to the speaker unit to thereby lower the level of a low frequency component of circumference noise output from the speaker unit. This headphone apparatus further includes an equalizer having a frequency characteristic substantially opposite to that of the filter, wherein an input audio signal is added to the negative feedback loop through the equalizer and then output from the speaker unit.